You can quit applications by using the Force Quit menu (⌘⌥ESC) but sometimes we need to quite a background application or the application on a remote machine. In Terminal we can do this using the top and kill commands.
Open Terminal
Type “top” and press return
Find the PID of the process to kill
If you can’t find the process try “top -o cpu -s 5” instead
Open a second Terminal window (⌘N)
Type “sudo kill [PID]”
Type “sudo kill [PID]”
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